Answer
$(3x-5y)(3x+5y)$
Work Step by Step
The given expression can be written as
$(3x)^2-(5y)^2.$
The expression above is a difference of two squares.
RECALL:
$a^2-b^2=(a-b)(a+b).$
Factor the difference of two squares using the formula above with $a=3x$ and $b=5y$ to obtain
$(3x-5y)(3x+5y).$
